Improvement in electric steam-boiler alarms



w. c. BAKER.

Electric Steam-Boiler Alarms.

Patented Apr No.l49, 907.

fie

UNITED STATES PATENT WILLIAM o. BAKER, oF New YORK, N. Y.

IMPROVEMENT IN ELECTRIC STEAM-BOILER ALARMS.

Specification forming part of Letters Patent No. 149,907, dated April 21, 1874; application filed March 21, 1874.`

To all whom it may concern:

Beit known that I, WILLIAM C. BAKER, of the city and State of New York, have invented an Improvement in Boiler-Alarms; and the following is declared to be a specification thereof.

The object of this invention is to furnish an alarm when the water of the boiler is too low, and also to indicate a pressure in excess of a defined amount.

I make use of an expansion-tube to close an electric circuit when the descent of the water in the boiler exposes that tube to the steam heat, and a diaphragm is employed to close the electric circuit if the pressure eX- ceeds a certain iXed point. In either instance the closing of the circuit causes an electromagnetic alarm to be rung at the engine-room, or in the oflice connected with the establishment, or in both places, so as to give a warning, and the alarm is so connected that by a circuit-closer voperated at the o'lice, or at any distant locality, the proprietor or other person can ascertain whether the apparatus isin workin g order without sounding the alarm in the engine-room. This apparatus may be employed by boiler-inspectors or others for indicating at a central office or station the condition of all the steam-boilersin a given district.

In the drawing, I have represented the apparatus for giving the alarm in section, and an elevation of the sounding alarms or bells and connections.

, f The boiler c has connecting-tubes b and c c, and 2, to the magnetic alarm h in the engine-room, and thence thelwire 3 passes to the alarm k'in the ofce or at the distant sta tion, and the current returns by the wire 4 to the battery, so that both alarms are sounded when the water descends below the established level. If the pressure of the steam exceed a predetermined limit, the diaphragm m is moved-sufciently to establish a metallic circuit from the battery through d and the case on and diaphragm m, to the insulated screw 6 `and wire 7, to the magnetic alarms h and k, so as to sound them as before. It' it is desired at the otiee or distant room to test the condition of the apparatus, the key .1", or cireuitelosing button, is pressed upon, which closes the circuit from the battery through the electro-magnet s and alarm k. An immediate response of the magnetic alarm 7c indicates that battery and connections are in order, and the electro-magnet s, acting upon its armature-lever t, link t', and lever u, will press the circuit-sprin g c into contact with the lever f, and the battery current will divide, a portion going through the magnetic alarm h hence, if the magnet s is of greater resistance than the magnet of h, there will also be an indication in the engine-room that the circuits are in workin g order; but if the electro-magnet s is of less resistance than that of the alarm h, the energy of the magnet ot' the latter will lnot be sutcient to sound the alarm, especially when the key or button r is only momentarily closed. The expansion low-water indicator may be of any desired character in which the change of temperature expands the metal and closes the circuit.

Iam aware that an electro-magnetic alarm has been employed with a pressure-gage, the circuit being closed by the hand; and, also, that a float has been connected with such alarm. These are not always reliable, because the delicate mechanism operating the hand of the pressure-gage is not to be depended upon ble to being rendered inoperative by sediment or otherwise.

I claim as my inventionl. The pressure-diaphragm and the lowwater expansion-tube, constructed and arranged substantially as speci tied, in combination with the cireuitclosers f and t, battery g, and magnetic alarms h k, substantially as set forth.

2. The circuit-closing button or key 1', electro-magnet s, levers t u, and connections, in combination with the magnetic alarm 7c, low- Water and pressure indicators, and connections from a galvanic battery, substantially as and for the purposes set forth.

3. The expansion low-Water indicator, in combination with a circuit-closer, electro-magnetic alarm, and battery,` substantially as set forth.

4. .The pressure-diaphragm m, located at or near the boiler, in combination with the insulated adjustable circuit-closer 6 and electromagnetic alarm, substantially as set forth.

5. An electro-magnetic alarm located at a distance from the boiler, and connected in a metallic circuit from a battery with a circuitclosing low-water expansion indicator at the boiler, and a circuit-closing pressure-indicating diaphragm, substantially as specified.

Dated March 17, A. D. 1874.

YV. C. BAKER.

Witnesses:

GEO. D. WALKER, GEO. T. PINOKNEY. 

